Fluid path containing a pressure isolation valve

ABSTRACT

A fluid path set including a multi-patient use section adapted for connection with a pump device and a source of injection fluid, and a per-patient use section adapted for removable fluid communication with the multi-patient use section. The per-patient use section includes a pressure isolation mechanism having a first port adapted for connection to the pump device via the multi-patient use section, a second port adapted for connection to a patient, and a pressure isolation port adapted for connection to a source of medical fluid via the multi-patient use section. The per-patient use section includes a valve member biased to a normally open position permitting fluid communication between the first port, the second port, and the pressure isolation port, and movable to a closed position to close the pressure isolation port when fluid pressure reaches a predetermined pressure level sufficient to overcome a biasing force applied to the valve member.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser.No. 11/238,666, filed on Sep. 29, 2005, now U.S. Pat. No. 8,747,358,issued Jun. 10, 2014, which is a divisional application of applicationSer. No. 09/982,518, filed on Oct. 18, 2001, now U.S. Pat. No.7,094,216, issued Aug. 22, 2006, which claims the benefit of ProvisionalApplication Ser. No. 60/241,505, filed on Oct. 18, 2000, the disclosuresof which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to powered injector systems and methodsfor use thereof in medical injection or fluid delivery procedures and,more particularly, to control of powered injector systems and methods ofcontrolling powered injector systems.

In many medical diagnostic and therapeutic procedures, a physician orother person injects a patient with a fluid. In recent years, a numberof injector-actuated syringes and powered injectors for pressurizedinjection of fluids such as contrast media have been developed for usein, procedures such as angiography, computed tomography, ultrasound andNMR/MRI. In general, these powered injectors are designed to deliver apreset amount of contrast media at a preset flow rate.

Angiography is used generally in the detection and treatment ofabnormalities or restrictions in blood vessels. In an angiographicprocedure, one obtains a radiographic image of vascular structure withthe assistance of a radiographic contrast medium (sometimes referred tosimply as contrast) injected through a catheter. The vascular structuresin fluid connection with the vein or artery in which the contrast isinjected are filled with contrast. X-rays passing through the region ofinterest are absorbed by the contrast, causing a radiographic outline orimage of blood vessels containing the contrast. The resulting images canbe displayed on, for example, a monitor and recorded.

In a typical angiographic procedure, a physician places a cardiaccatheter into a vein or artery. The catheter is connected to either amanual or an automatic contrast injection mechanism. A typical manualcontrast injection mechanism includes a syringe and a catheterconnection. The operator of such a syringe adjusts the flow rate andvolume of injection by altering the force applied to the plunger of thesyringe. Manual sources of fluid pressure and flow used in medicalapplications such as syringes and manifolds thus typically requireoperator effort that provides feedback of the fluid pressure/flowgenerated to the operator. The feedback is desirable, but the operatoreffort often leads to fatigue. Thus, fluid pressure and flow may varydepending on the operator's strength and technique.

Automatic contrast injection mechanisms typically include a syringeconnected to a powered injector having, for example, a powered linearactuator. Typically, an operator enters into an electronic controlsystem of the powered injector a fixed volume of contrast material and afixed rate of injection. In many systems, there is no interactivecontrol between the operator and the powered injector, except to startor stop the injection. A change in flow rate in such systems occurs bystopping the machine and resetting the parameters. Automation ofangiographic procedures using powered injectors is discussed, forexample, in U.S. Pat. Nos. 5,460,609, 5,573,515 and 5,800,397.

U.S. Pat. No. 5,800,397 discloses an angiographic injector system havingboth high pressure and low pressure systems. The high pressure systemincludes a motor-driven injector pump to deliver radiographic contrastmaterial under high pressure to a catheter. The low pressure systemincludes, among other things, a pressure transducer to measure bloodpressure and a pump to deliver a saline solution to the patient as wellas to aspirate waste fluid. A manifold is connected to the syringe pump,the low pressure system, and the patient catheter. A flow valveassociated with the manifold is normally maintained in a first stateconnecting the low pressure system to the catheter through the manifold(and disconnecting the high pressure system from the catheter and thelow pressure system). When pressure from the syringe pump reaches apredetermined and set level, the valve switches to a second stateconnecting the high pressure system/syringe pump to the catheter, whiledisconnecting the low pressure system from the catheter (and from thehigh pressure system). In this manner, the pressure transducer isprotected from high pressures. See Col 3, lines 20-37. However,compliance in the system components (for example, expansion of thesyringe, tubing and other components under pressure) using such amanifold system can lead to a less than optimal injection bolus.Moreover, the arrangement of the system components of U.S. Pat. No.5,800,397 results in relatively large amounts of wasted contrast and/orundesirable injection of an excessive amount of contrast when the lowpressure (saline) system is used.

The injector system of U.S. Pat. No. 5,800,397 also includes a handheldremote control connected to a console. The control includes saline pushbutton switches and a flow rate control lever or trigger. By progressivesqueezing of the control trigger, the user provides a command signal tothe console to provide a continuously variable injection ratecorresponding to the degree of depression of the control trigger.

Similarly, U.S. Pat. No. 5,916,165 discloses a handheld pneumaticcontroller for producing a variable control signal to control a rate offluid disbursement to the patient in an angiographic system. U.S. Pat.No. 5,515,851 discloses an angiographic system with a finger activatedcontrol pad to regulate the injection of fluids.

Unlike manual injection systems, however, there is little if anyfeedback to the operator of system pressure in the above systems. Thereare potential advantages to such feedback. In the use of a manualsyringe, for example, excessive backpressure on the syringe plunger canprovide evidence of occlusion of the fluid path.

U.S. Pat. No. 5,840,026 discloses, among other things, an injectionsystem in which an electronic control system is connected to thecontrast delivery system and a tactile feedback control unit. In oneembodiment, the tactile feedback control unit includes a disposablesyringe that is located within a durable/reusable cradle and is in fluidconnection with the fluid being delivered to the patient. The cradle iselectrically connected to the electronic control system and isphysically connected to a sliding potentiometer that is driven by theplunger of a disposable syringe.

During use of the injection system of U.S. Pat. No. 5,840,026, thedoctor holds the cradle and syringe and, as the doctor depresses thesliding potentiometer/syringe piston assembly, the plunger is movedforward, displacing fluid toward the patient and creating a pressure inthe syringe. A sliding potentiometer tracks the position of the syringeplunger.

The electronic control system controls the contrast delivery system toinject an amount of fluid into the patient based on the change inposition of the plunger. As the fluid is injected, the pressure thedoctor feels in his hand is proportional to the actual pressure producedby the contrast delivery system. The force required to move the pistonprovides the operator with tactile feedback on the pressure in thesystem. The doctor is able to use this feedback to ensure the safety ofthe injection procedure.

Unlike the case of a manual injection system, the injection system ofU.S. Pat. No. 5,840,026 does not require the doctor to develop thesystem pressure and flow rate. The doctor develops a smaller, manuallyapplied pressure, which corresponds to or is proportional to the systempressure. The required manual power output (that is, pressure×flow rate)is decreased as compared to manual systems, whereas the tactile feedbackassociated therewith is retained.

Although advances have been made in the area of angiographic injectionsystems, it remains desirable to develop injectors, injector systems andmethods to facilitate such procedures.

SUMMARY OF THE INVENTION

The present invention provides an injector system including a poweredinjector, a pressurizing chamber in operative connection with thepowered injector, a fluid path in fluid connection with the pressurizingchamber, and a manual control in fluid connection with the fluid path.The manual control includes at least one actuator for controlling theinjector through application of force by an operator. The actuatorprovides tactile feedback of pressure in the fluid path to the operatorvia direct or indirect operative or fluid connection with the fluid path(that is, pressure in the fluid path transfers a corresponding or aproportional force to the operator). In one embodiment, the actuator isadapted to stop an injection procedure if no force is applied to theactuator. The manual control can, for example, include a chamber influid connection with the fluid path. The actuator can be a button or aplunger in operative connection with a piston disposed within thechamber. The actuator can be biased in an off position.

In another aspect, the manual control includes a first actuator forcontrolling the injector in a low-pressure mode through application offorce by an operator. The first actuator provides tactile feedback ofpressure in the fluid path to the operator via fluid connection with thefluid path as described above. The first actuator also provides controlof flow rate by changing the force thereon. The manual control also caninclude a second actuator having an on state and an off state. Thesecond actuator causes the injector to enter into a preprogrammedhigh-pressure injection mode when placed in the on state. The manualcontrol can also include a third actuator for controlling flow of salinein the fluid path.

In another aspect of the present invention, the actuator providestactile feedback of fluid pressure and is also in operative connectionwith an audible feedback unit that provides audible feedback of fluidpressure and/or fluid flow to the operator. The manual controls of thepresent invention can be purged of air before injection via, forexample, a purge valve.

The present invention also provides a system for injection of fluid intoa patient including a multi-patient reusable section and a per-patientdisposable section. The multi-patient reusable section and theper-patient disposable section are removably connectable via a connectoror connectors (for example, via a high-pressure connector). Themulti-patient reusable section includes a powered injector in fluidconnection with a source of a first injection fluid and a first fluidpath connecting the injector and a high-pressure connector. Theper-patient disposable section includes a second fluid path adapted toconnect the high-pressure connector and the patient in fluid connection.The per-patient disposable section further includes a manual control asdescribed above including a connector to place the manual control influid connection with the second fluid path. The multi-patient reusablesection can further include a valve mechanism connecting the injector,first fluid source and the first fluid path.

In one embodiment, the multi-patient reusable section further includes asource of a second injection fluid and a pumping mechanism in fluidconnection with the second fluid source for pressurizing the secondfluid. The pumping mechanism is preferably in fluid connection with thevalve mechanism.

In one aspect, the manual control includes a first actuator providingcontrol of flow rate of the first fluid by changing the force on thefirst actuator and a second actuator, the second actuator causing theinjector to enter into a preprogrammed high pressure injection mode whenplaced in an on state. The system can further include a pressure sensorin fluid communication with the second fluid path via apressure-activated isolator that isolates the pressure sensor frompressures in the second fluid path above a set pressure. In oneembodiment, the per-patient disposable section can include a check valvein the second fluid path separating components of the per-patientdisposable section from the multi-patient reusable section to reduce oreliminate flow of contaminated fluid into the multi-patient reusablesection.

The present invention further provides a method of injecting a fluidinto a patient including the steps of: removably connecting amulti-patient reusable section to a per-patient disposable section via ahigh-pressure connector, the multi-patient reusable section including apowered injector in fluid connection with a source of a first injectionfluid and a first fluid path connecting the injector and thehigh-pressure connector, the per-patient disposable section including asecond fluid path adapted to connect the high-pressure connector and thepatient in fluid connection; connecting a manual control including aconnector to the second fluid path to place the manual control in fluidconnection with the second fluid path, the manual control including atleast one actuator for controlling the powered injector throughapplication of force by an operator, the actuator being adapted toprovide tactile feedback of pressure in the second fluid path to theoperator via fluid connection with the second fluid path; and injectinga fluid into a patient.

The method can further include the step of connecting a pressure sensorin fluid communication with the second fluid path via a pressureactivated isolator that isolates the pressure sensor from pressures inthe second fluid path above a set pressure.

Still further, the present invention provides a per-patient disposableset for use in an injection procedure including a fluid path adapted toform a fluid connection between a high-pressure connector and thepatient, and a manual control in fluid connection with the fluid path.The manual control includes at least one actuator for controlling thepowered injector through application of force by an operator. Theactuator is adapted to provide tactile feedback of pressure in the fluidpath to the operator via fluid connection with the fluid path. Theper-patient disposable set further includes a pressure sensor in fluidconnection with the fluid path via a pressure activated isolator adaptedto isolate the pressure sensor from pressures in the fluid path above aset pressure.

The manual (for example, handheld) controllers of the present inventionprovide a number of advantages including, but not limited to thefollowing: tactile feedback of actual fluid path pressure via fluidcommunication with the fluid path, compact size and small primingvolume; dead man switch capability; ergonomic design for control of bothcontrast and saline; injection pressure feedback linked to variable flowand audible feedback; rigid material construction; actuator controlproviding a progressively increasing flow rate as the actuator is pushedor depressed through its range of motion; and high-pressure injectionsthat are greater in pressure than could be tolerated by an operator'shand.

In another aspect, the present invention provides an injection systemfor use in angiography including a powered injector in fluid connectionwith a source of injection fluid and a pressure sensor in fluidconnection with the powered injector via a pressure activated isolatoradapted to isolate the pressure sensor from pressures in the fluid pathabove a set pressure. The pressure sensor elevation is independent of orindependently variable of the position of the remainder of the injectionsystem, including the position or elevation of the powered injector.

In a further aspect, the present invention provides an angiographicinjection system for injecting an injection fluid into a patientincluding a pressurizing device for supplying injection fluid underpressure; a low pressure fluid delivery system; and a pressure isolationmechanism having a first port for connection to the pressurizing device,a second port for connection to the patient, and a third port forconnection to the low pressure fluid delivery system. The pressureisolation mechanism includes a valve having a first state and a secondstate different from the first state. Preferably, the first state andthe second state are mutually exclusive of each other. The first stateoccurs when the second and third ports are connected and the first andthird ports are connected. The second state occurs when the first andsecond ports are connected and the first and third ports aredisconnected. The valve is normally biased to the first state (via, forexample, a spring) and is switchable to the second state when fluidpressure from the syringe pump reaches a predetermined pressure level.The first and second ports remain connected in the first state and inthe second state.

The system preferably further includes a valve in line between thepressurizing device and the first port of the pressure isolationmechanism to control flow of the injection fluid. Preferably, the valveis an automated valve. The valve is preferably operable to minimize oreliminate the effects of compliance of the pressurizing device andrelated tubing.

The low pressure delivery system can include a source of saline or othersuitable flushing medium, a drip chamber in fluid connection with thesource of saline and a detector to sense the amount of saline in thesource of saline. The system can further include a saline control valveand an air detector in line between the saline drip chamber and thepressure isolation mechanism.

The pressurizing device can be in fluid connection with a source ofinjection fluid via an injection fluid drip chamber. The system canfurther include a detector to sense the amount of injection fluid in thesource of injection fluid. Likewise, the system can also include aninjection fluid control valve and an air detector in line between theinjection fluid drip chamber and the pressure isolation mechanism.

In one embodiment, the system further includes a handheld controller tocontrol injection of injection fluid and injection of saline. Thehandheld controller can include a first control having a first mode tocontrol injection of injection fluid in a low pressure mode, the flowrate of the injection corresponding to (for example, being proportionalto) the distance the first control is depressed. Preferably, the lowpressure injection is ceased if the first control is released while inthe first mode. The first control can, for example, have a second modeto control injection of injection fluid in a high pressure mode. Thehigh pressure mode injection is preferably ceased if the first controlis released while in the second mode. The hand controller can furtherinclude at least a second control to control injection of saline.Preferably, the injection of saline is ceased if the second control isreleased during injection of saline.

The system preferably further includes a pressure transducer in fluidconnection with the third port of the pressure isolation mechanism.

In still a further aspect, the present invention provides an injectionsystem for use in angiography including a source of saline, a pump influid connection with the source of saline to pressurize the saline, asaline valve in fluid connection via a first port thereof with an outletof the pump, a first connector in fluid connection with a second port ofthe saline valve, a source of contrast, a contrast valve in fluidconnection with the source of contrast via a first port of the contrastvalve, a powered injector in fluid connection with a second port of thecontrast valve, a second connector in fluid connection with a third portof the contrast valve, and a pressure isolation mechanism.

The pressure isolation mechanism has a lumen having a first port influid connection with the second connector and a second port in fluidconnection with a patient catheter. The isolation mechanism further hasa third port in fluid connection with the first connector and with thelumen. The pressure isolation mechanism further includes a valve havinga first state and a preferably mutually exclusive second state—the firststate occurring when the lumen and the third port are connected, and thesecond state occurring when the lumen and the third port aredisconnected. The valve is preferably normally biased to the first stateand is switchable to the second state when fluid pressure from thepowered injector reaches a predetermined pressure level. The first andsecond ports of the lumen preferably remain connected whether in thefirst state or in the second state. The system further includes apressure transducer in fluid connection with the third port of thepressure isolation mechanism.

The system can also include a first air or air column detector in fluidconnection between the saline valve and the first connector and a secondair detector in fluid connection between the contrast valve and thesecond connector.

The system can also include a first drip chamber in fluid connectionbetween the source of saline and the pump and a detector in operativeconnection with the first drip chamber to sense the amount of saline inthe source of saline. Likewise, the system can include a second dripchamber in fluid connection between the source of contrast and thecontrast valve and a detector in operative connection with the seconddrip chamber to sense the amount of injection fluid in the source ofinjection fluid. One advantage of a drip chamber is to reduce likelihoodof introduction of air into the system once the system has beeninitially purged or air or primed.

Numerous other objects and advantages of the present invention will beapparent from the following drawings and detailed description of theinvention and its preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates one embodiment of an injection system of the presentinvention.

FIG. 2 illustrates an embodiment of a pressure activated isolatorassembly of the present invention.

FIG. 3 illustrates an embodiment of a handheld controller or hand pieceof the present invention.

FIG. 4 illustrates another embodiment of a handheld controller of thepresent invention in which the handheld controller is connected to thefluid path via a “T” connection.

FIG. 5A illustrates another embodiment of a handheld controller of thepresent invention including a control switch for pressure feedback inlow pressure injection, a switch for high pressure injection and aswitch for saline injection.

FIG. 5B illustrates another embodiment of a handheld controller of thepresent invention, which is wearable on a finger of the user.

FIG. 6A illustrates a schematic representation of another embodiment ofan injection system of the present invention.

FIG. 6B illustrates a side view of an embodiment of a portion of theinjection system of FIG. 6A in which a pressure transducer is in thefluid path.

FIG. 6C illustrates a side view of an embodiment of a portion of theinjection system of FIG. 6A in which a pressure transducer is separatedfrom the fluid path by a T-connector and a length of tubing.

FIG. 6D illustrates a side cross-sectional view of an embodiment of apressure isolation valve of the present invention in which the valve isin a first, “open” state.

FIG. 6E illustrates a side cross-sectional view of the pressureisolation valve of FIG. 6D in which the valve is in a second, “closed”state.

FIG. 6F illustrates a perspective view of the pressure isolation valveof FIGS. 6D and 6E.

FIG. 6G illustrates a front view of the injection system of FIG. 6A.

FIG. 6H illustrates a front view of the handheld controller of theinjection system of FIG. 6A.

DETAILED DESCRIPTION OF THE INVENTION

In one aspect, the present invention provides an energy/signal source togenerate fluid pressure/flow while also providing user tactile and/oraudible feedback of the fluid pressure generated, allowing the user tomodulate the fluid pressure/flow. The powered injection system of thepresent invention is capable of providing, for example, both preciselow-flow/low-pressure fluid delivery for powered coronary injections andhigh-flow/high-pressure fluid delivery for ventricle injections.

FIG. 1 illustrates one embodiment of the present invention in whichinjector system 10 is preferably divided into two sections: A) amulti-patient section or B) set and a per-patient disposable section orset. Section or set A and section or set B are preferably separated andremovably coupled into fluid connection by a high-pressure connector orby a high-pressure, “aseptic” connector 20 such as the septum connectordisclosed in U.S. Pat. No. 6,096,011, assigned to the assignee of thepresent invention, the disclosure of which is incorporated herein byreference. The aseptic coupler or connector of U.S. Pat. No. 6,096,011is suitable for repeated use (coupling and uncoupling) at relativelyhigh pressures. Aseptic connector 20 preferably maintains a leakproofseal at high pressures after many such uses and can, for example,include a surface that can be disinfected (for example, betweenpatients) by wiping with a suitable disinfectant. Another high-pressureaseptic connector suitable for use in the present invention is disclosedin U.S. patent application Ser. No. 09/553,822, filed on Apr. 21, 2000,assigned to the assignee of the present invention, the disclosure ofwhich is incorporated herein by reference.

Multi-patient set A preferably includes a powered injector 30 which istypically an electromechanical drive system for generating fluidpressure/flow via, for example, a pressurizing chamber such as syringe40 as known in the art. Suitable powered injectors and syringes for usein the present invention are disclosed, for example, in PCT PublicationNo. WO 97/07841 and U.S. Pat. No. 4,677,980, assigned to the assignee ofthe present invention, the disclosures of which are incorporated hereinby reference.

In general, the injector drive is an electromechanical device thatcreates linear motion acting on a syringe plunger (not shown in FIG. 1)to provide the generation of fluid pressure/flow. A source of injectionmedia 60 (for example, a contrast bottle) is in fluid connection withthe syringe via, for example, an electromechanical valve assembly 50 forcontrolling and directing fluid flow by acting upon preferablydisposable valves 52 and 54. Valves 52 and 54 are preferablymulti-position valves that are fluid wetted. Valves 52 and 54 canalternatively or additionally be manually operated. Contrast bottle orcontainer 60 can be prepackaged contrast media, often distributed in aglass or plastic container with a rubber septum for allowing connectionsvia IV spikes. An interim container or reservoir 70 is preferably placedbetween contrast bottle 60 and electromechanical valve assembly 50 toprovide an air gap in the fluid path to enable purging of air from thesystem and to allow level detection of contrast source 60. Interimreservoir 70 can operate in conjunction with a contrast level detectionsystem as described in further detail below. A contrast level detector80 can, for example, include one or more electrical, optical,ultrasound, or mechanical sensors that detect the presence of fluid at acertain level in interim reservoir 70.

Further protection against injection of air into a patient can beprovided by variety of mechanisms for detection of air in the fluid pathor stream. For example, ultrasonic bubble detection can be used todetect the presence of air in the fluid path. Likewise, backlighting canbe used for bubble detection. In the backlighting method of bubbledetection, the injector side of the fluid path is illuminated toincrease visualization of the fluid path, fluid presence and airpresence.

At least one source 90 of another fluid (typically saline or othersuitable medium) can also be provided. Additional fluid sources, such astherapeutic fluids, can also be provided. Additional fluid sources suchas saline supply 90 are preferably in operative or fluid connection witha pressurizing mechanism such as a powered injector or a peristalticpump 100. In FIG. 1, peristaltic pump 100 in operative connection withthe saline source 90 is in fluid connection with the fluid path ofinjector 30 via electromechanical valve assembly 50.

A controller unit 200 provides power to injector 30 and to peristalticpump 100 in a controlled manner. Controller unit 200 providescommunication between the various system components. A graphical userinterface display 210 is preferably provided in connection withcontroller unit 200 to display information to the user and to enable theuser to set and adjust device parameters. An audible feedback source 220can be provided, for example, to provide feedback to the user of therate of flow provided by injector 30. For example, a sound can increasein pitch, volume and/or frequency as flow rate is increased.

Per-patient disposable set B includes fluid wetted components of thefluid delivery path. Per-patient disposable set B preferably includes awaste port 310 (for example, through which patient blood can be drawn),a pressure measurement port 320, and an interface 330 to a catheter 340(for example, a connector such as a standard Luer connector). Waste port310 can, for example, include a manually activated or automated valve toallow discharge of unwanted fluid and connection of, for example,manually operated syringes. Moreover, a powered aspiration mechanism(for example, a peristaltic pump 314 connected via tubing to a waste bag316) can be connected to waste port 310 via, for example, a standardconnector 312, to aspirate fluid from the system as well as to drawblood from the patient. Drawing fluid from the system and blood from thepatient into waste bag 316 assists in eliminating air from the fluiddelivery system.

Pressure port 320 preferably includes a pressure-activated isolator 350for pressure transducer isolation as, for example, illustrated in FIG.2. Pressure-activated isolator 350 is a fluid activated assembly that islocated in line with the injection flow. In the embodiment of FIG. 2, avalve 352 within the assembly isolates pressure transducer 360 byshutting off during high-pressure injections. A spring 354 returns valve352 to its original open position when the injector system is notinjecting at high pressure, thus opening the fluid path to pressuretransducer 360. In the embodiment of FIGS. 1 and 2, pressure-activatedisolator 350 transitions to a closed position to isolate only pressuretransducer 360, which is not in fluid connection with contrast source 60or saline source 90 other than through pressure-activated isolator 350.Pressure transducer 360 can, for example, be located near the patient tosubstantially reduce or remove pressure signal dampening resulting fromintervening tubing, fluid and system components and thereby improveaccuracy as compared to other pressure measurement systems currentlyused in angiographic procedures. Preferably, pressure transducer 360 isseparated by a minimum (for example, by no more than approximately threefeet) of tubing from the patient/catheter connector. Because of themulti-patient nature of set A, the pressure transducer assembly and theremainder of per-patient disposable set B are preferably locateddownstream of a double check valve 370 to provide continuousmeasurements. As such, a pressure isolation mechanism such as describedabove is required to isolate pressure transducer 360 from high pressureduring power injection.

The system also includes a manually operated, for example, a handheld orhand operated, control 400 that can, for example, generate or process acontrol signal that is electrical, mechanical, pneumatic, optical, radiofrequency, audible or any combination thereof to effect control ofinjector 30 and preferably to also effect control of peristaltic pump100. Handheld control 400 also preferably provides feedback (forexample, tactile, visual, audible etc.) of the injected fluid pressureand flow to the operator. Handheld control 400 preferably provides atleast tactile feedback. In the embodiments of FIGS. 1, 3 and 4, thehandheld control or hand piece is in operative communication with thefluid flow and allows the user to feel the pressure in the fluid pathline. Preferably, an electrical switch allows the user to turn on/offand modulate the fluid/flow pressure of the system forlow-pressure/low-flow coronary injections only. High-pressure injectionis activated, for example, using either display 210 or a separate(second) control on the handheld control. The handheld control thusprovides pressure feedback to the user while controlling the injection.

The handheld controls of the present invention can, for example, includea fluid path containment chamber in which a movable element is able totravel a pre-determined distance. The moveable element is preferably indirect contact with the fluid path and is affected by fluid flow andpressure. The movable element incorporates a mechanism to process asignal, which can be used to control the fluid pressure/flow sourceremotely. The handheld device is capable of being used with a signalprocessor related to the movement of the moveable element as known inthe art.

In one embodiment of the present invention, a handheld control device500 incorporates a moveable piston 510 slideably disposed within achamber 520 in a direction generally perpendicular to the direction offluid flow as illustrated in FIG. 3. Chamber 520 and piston 510 can bedirectly in the fluid path or can be spaced from the fluid path by alength of tubing (see, for example, FIG. 4). Handheld device 500 allowsmoveable piston 510 to be positioned under one finger while device 500is held in the hand. Piston 510 preferably incorporates a switch 530that, when compressed, controls the fluid flow generated by an externalfluid pressure/flow source (for example, injector 30). Upon generationof the pressure, piston 510 is displaced by increased pressure, which isdetectable by the operator. Further compression of piston 510 by theoperator preferably increases the signal to the fluid flow/pressuregenerator, resulting in an increase in the pressure/flow and anincreased pressure on piston 510, which is felt by the operator.Backpressure or tubing occlusion causes increased pressure in thesystem, upward movement of piston 510 and tactile feedback to theoperator, thereby alerting the operator to potential problems in theinjection procedure. The system can also provide audible and/or visualfeedback of the flow rate via, for example, user display 210 that ispreferably controlled by the position of piston 510.

As illustrated in FIG. 4, a handheld control 500′ can be connected in a“T” 550 off of the main line for more flexibility. A purge valve 540 canbe located at the end of handheld control 500′ for air eliminationduring system purge. Air can also be purged from the handheld control500′ before it is connected to the fluid path. FIG. 4 also illustrates asecond switch 560′ for initiation of a high pressure injection. Anadditional switch or switches can also be provided to, for example,control delivery of saline.

FIGS. 5A and 5B illustrate other, ergonomic handheld controls. Handheldcontrol 600 of FIG. 5A includes a chamber 620 that can be in fluidconnection with the injection system fluid path as described above. Alow pressure control switch 610 similar in operation to piston 510 isslideably disposed within chamber 620 to control low-pressure injectionsof contrast. Chamber 620 can, for example, be formed to conform to thehand of the user. A switch 630 to begin a high pressure injection viainjector 30 is provided on handheld control 600. Also, a switch 640 tocontrol delivery of saline is provided on handheld control 600.

FIG. 5B illustrates an embodiment of a finger-wearable handheld control700. In that regard, a finger of the user's hand passes through passage710 in control 700 while control 700 is held in the user's hand. Arotating switch 720 controls low-pressure injection. A high pressureinjection switch 730 and a saline switch 740 are also provided.

System 10 can also include a manually operated foot controller 420including one or more actuators 430 in communication with controller200. Foot controller 420 can, for example, be used to control flowthrough system 10 in conjunction with or independently of handheldcontroller 400.

Another embodiment of an injector system 800 is illustrated in FIGS. 6Athrough 6H. In this embodiment (referring primarily to FIGS. 6A and 6G),a fluid control module 810 is in operative connection with a poweredinjector 830 to which a syringe 840 is connected as described above.Syringe 840 is in fluid connection with an automated valve 852 of fluidcontrol module 810, which is also in fluid connection with a source ofcontrast 860 via an intermediate drip chamber 870. Drip chamber 870preferably includes a fluid level sensing mechanism 880. A preferablyautomated valve/stopcock 852 such as known in the art is also in fluidconnection with a first, inlet port of a lumen 954 of a pressureisolation valve 950. Valve 852 prevents saline and/or contaminatedfluids from entering syringe 840 and enables the operator to stop flowof injection fluid (for example, contrast) from syringe 840 quickly atany pressure or flow rate. This ability to substantially immediatelystop flow of injection fluid at any pressure and flow rate substantiallyremoves the effects of system compliance and enables delivery of a“sharp” bolus. An air column detector 856 can be placed in line betweenstopcock 852 and pressure isolation valve 950.

Fluid control module 810 further includes a source of saline 890 influid connection with a peristaltic pump 900 via an intervening dripchamber 910. Drip chamber 910 preferably includes a fluid level sensingmechanism 920. Peristaltic pump 900 is in fluid connection with apreferably automated valve/stopcock 854, which is in fluid connectionwith pressure isolation valve 950. In addition to controlling flow ofsaline, valve 854 prevents contaminated fluids from reaching peristalticpump 900 and saline source 890. An air column detector 858 can be placedin line between stopcock 854 and pressure isolation valve 950.

A controller 970 and a display 974 (see FIG. 6A) are also in operativeconnection with injector 830 as described above. Furthermore, handheldcontroller 1000 is in operative connection with injector 830 and therebywith fluid control module 810. In the embodiment of FIGS. 6A through 6H,handheld controller 1000 does not provide tactile feedback of systempressure to the operator. However, a handheld controller providing suchtactile feedback (for example, handheld controller 600) can readily beused in connection with system 800. Moreover, a foot controller asdescribed above can also be provided.

In general, the preferably per-patient disposable portion or set ofsystem 800 is illustrated within dashed lines in FIGS. 6A, 6B, 6C and6G. Two connectors 990 a and 990 b (which are preferably asepticconnectors as described above) are used to connect the multi-patientfluid path set with the per-patient fluid path set. Use of twoseparate/parallel fluid lines and two separate connectors to connect themulti-patient set with the per-patient disposable set affords a numberof benefits over current angiographic injection systems includingdecrease contrast wastage and avoidance of injecting potentiallyhazardous amounts of contrast into the patient during saline purges.Moreover, system 800 facilitates close placement of pressure transducer980 to the patient, improving measurement accuracy as compared tocurrently available systems. Although handheld controller 1000 in theembodiments of FIGS. 6A through 6H is not in direct connection with thefluid path, it is preferably disposable because of contamination withbodily fluids that typically occurs from operator handling thereof.

Lumen 954 (via a second, outlet port thereof) of pressure isolationvalve 950 is preferably in fluid connection with an automated or manualvalve/stopcock 994, which preferably includes a waste port 996 asdescribed above. Catheter 1100 is preferably connected via a rotatingLuer connection 998.

FIG. 6B illustrates a portion of a fluid path set for use in system 800of FIG. 6A in which a pressure transducer 980 is directly in the salinefluid path. FIG. 6C illustrates a fluid path set for use in system 800of FIG. 6A in which pressure transducer 980 is separated from the salinefluid path by a “T” connector 952 and a length of tubing 954. In theembodiments of FIGS. 6B and 6C, spikes 976 a and 976 b are used toconnect to contrast source 860 and saline source 890, respectively. Ingeneral, standard Luer connections are used to connect most of thecomponents of system 800. In FIGS. 6B and 6C several of these Luerconnections are illustrated in a disconnected state. Alternatively, oneor more of the illustrated connections can, for example, be non-Luer orbonded connections.

One embodiment of a pressure isolation valve 950 is illustrated in FIGS.6D through 6F. Pressure isolation valve 950 includes a housing 952 witha high pressure lumen 954, through which fluid passes under pressure.Pressure isolation valve 950 also includes a port 956 to which pressuretransducer 980 and saline source 890 are connected. A piston 958 acts toisolate pressure transducer 980 once a given pressure is reached inlumen 954 of pressure isolation valve 950. In an “open” or rest state,as shown in FIG. 6D, there is hydraulic or fluid communication betweenlumen 954 (including catheter 1100 and syringe 840 connected thereto),and isolation port 956 (including pressure transducer 980 and the salinefluid path connected thereto).

Preferably, the clearances and apertures within pressure isolation valve950 are sufficiently generous to transmit changes in pressure thatnormally occur during normal heart function quickly, as to not damp thesignal. The pressure effect on piston 958 of the flow of injection fluidfrom syringe 840 through lumen 954 is illustrated with dashed arrows inFIG. 6D while the flow of saline through pressure isolation mechanism950 is illustrated with solid arrows. When the pressure within lumen 954increases during an injection, piston 958 responds by moving to theright in the orientation of FIGS. 6D and 6E, compressing a spring 960until a seal portion 962 at the left end of piston 958 contacts asealing seat 964 as illustrated in FIG. 6E. At this point, lumen or port956 is isolated from lumen 954 and any additional increase in pressureacts to increase or improve the effectiveness of the seal 962. When thepressure within 10 lumen 954 subsides, spring 960 reopens pressureisolation valve 950 by pushing piston 958 to the left. In oneembodiment, fluid does not flow through port 956. In this embodiment,pressure isolation valve 950 only isolates the tubing and devices distalto port 956 from high pressure and does not control flow.

As discussed above, saline is used occasionally during routinecatheterization procedures. For example, controls 1030 a or 1030 b onhandheld control 1000 can send a signal to control the flow of saline.For patient safety, it is desirable to introduce the saline close to theproximal end of catheter 1100 so the amount of contrast purged ahead ofthe saline is minimized during a saline injection. Once again, theparallel line configuration of the contrast delivery and saline deliverfluid paths of present invention assist in preventing such undesirableinjections.

Since the required saline flow rates are low and the viscosity of salineis much lower than the viscosity of contrast, the pressures required toforce saline through catheter 1100 are much less than that of contrast.By protecting the saline line from the high pressures required forcontrast injection, additional system compliance is avoided and thesaline line does not need to be made of the same high-pressure line asthe contrast. Protection of the saline line from high pressure isaccomplished by connecting the saline line to port 956 of pressureisolation valve 950 to introduce the saline flow as illustrated withsolid arrows in FIG. 6D. In this embodiment, port 956 is normally open,permitting the flow of saline therethrough, when required, as well asthe monitoring of the patient blood pressure. During a high-pressureinjection, pressure isolation valve 950 functions as described above andprotects pressure transducer 980 and the low-pressure saline line fromthe high contrast injection pressures.

The elevation of catheter 1100 often changes during the course of aninjection procedure, for example, as the patient is raised or lowered.Such changes in elevation of catheter 1100 can result in erroneous bloodpressure readings by pressure transducer 980. Therefore, pressuretransducer 980 is preferably positioned such that it changes elevationwith catheter 1100 and is not dependent upon the position of theinjection system, including the position of injector 830.

In one embodiment in FIGS. 6G and 6H, handheld controller 1000 includeda plunger or stem control 1010 that, when in a first/low pressure mode,is depressed by the operator to control the flow of contrast fromsyringe 840. The farther plunger 1010 is depressed, the greater the flowrate (via, for example, a potentiometer such as a linear potentiometerwithin housing 1020 of controller 1000). In this embodiment, theoperator can use graphical user interface display 974 to change the modeof plunger 1010 to a second mode in which it causes injector 830 toinitiate a high pressure injection as preprogrammed by the operator. Inthis second/high pressure mode, the operator maintains plunger 1010 in adepressed state to continue the injection. Preferably, if plunger 1010is released, the high-pressure injection is terminated substantiallyimmediately, for example, by control of valve 852. Handheld controller1000 also includes at least one switch to control saline flow in system800. In the embodiment of FIG. 6H, handheld controller 1000 includes twosaline switches 1030 a and 1030 b on either side of plunger 1010 forease of access by the operator. In this embodiment, switches 1030 a and1030 b include resilient cantilevered members 1032 a and 1032 b,respectively, which are depressed by the operator to deliver salinethrough system 800. Preferably, one of switches 1030 a or 1030 b must bemaintained in a depressed state by the operator to continue delivery ofsaline. If the depressed switch is release, saline flow is preferablystopped substantially immediately, for example, via control of valve854.

As illustrated in FIG. 6G, many of the components of system 800 can besupported on a mobile stand 805. Injector 830 is preferably rotatableabout stand 805 as indicated by the arrow of FIG. 6G. In one embodimentof system 800 of FIGS. 6G and 6H: stopcocks were obtained from MedicalAssociates Network, Inc., a distributor for Elcam Plastic, under productnumber 565302; spikes were obtained from Qosina under product numbers23202 and 23207, tubing was obtained from Merit Medical under productnumbers DCT-100 and DCT-148; connectors were obtained from Merit Medicalunder product number 102101003, a rotating hub was obtained from MedicalAssociates Network, Inc., a distributor for Elcam Plastic, under productnumber 565310; a peristaltic, pump from Watson-Marlow was obtainedhaving a product number of 133.4451.THF; and fluid level sensors fromOmron were obtained under product number EESPX613.

The following describes a typical use scenario of injection systems ofthe present invention and assumes that all fluid path components areassembled/connected and located in their proper position, includingcontrast and saline containers.

Typically, the first step in an injection procedure is replacing air inthe fluid path with fluid. By operator initiation and machine control,the powered injector causes the syringe plunger to move rearward (towardthe powered injector), thereby creating a negative pressure at theconnection point to a control valve in proximity to the contrast interimcontainer. The control valve is positioned to allow fluid flow from thecontrast bottle, into the interim container and into the syringe. Upondrawing a predetermined amount of contrast into the syringe, theinjector drive preferably reverses direction creating a positivepressure and fluid movement in the direction of the contrast containeror the catheter (which is not connected to a patient) to drive anyentrapped air out of the fluid path into an “air gap” established in theinterim container or through the catheter. Air is further preferablyinitially purged from the system during start-up by, for example,distributing a fluid such as saline through the fluid path (sometimesreferred to as “priming”). The system is preferably maintained air-freeduring an injection procedure and with multi-patient use. Priming ispreferably done once per patient or once per multi-patient, depending ondisposable fluid path configuration.

The system can include, for example, “contrast low” level (need forrefill) and “stop filling” limit sensors on the interim reservoir asdescribed above to help ensure that air is not aspirated into thecontrast syringe during a fill cycle. An ultrasonic air column sensor orsensors and/or other types of sensors can also be included downstream ofthe injector to detect air gaps within the line as a secondary safetysensor.

By operator initiation and machine control, a second fluid pumpconnected to a bulk source of saline, typically a prefilled bag,provides fluid flow in the direction of patient catheter. Enough salineis preferably pumped throughout disposable set to achieve elimination ofall visible air during priming. Using the saline priming feature, ahandheld controller that is in fluid connection with the fluid path (toprovide tactile feedback as described above) can, for example, be purgedof air by opening an integral bleed valve. After priming is complete thebleed valve is closed.

Once the system is properly set up and primed, it can be connected tothe patient via the catheter. The system preferably has a range ofparameters for flow, pressure, variable flow, alarms and performancelimits as known in the art.

To deliver contrast at low flow and low pressure, for example, to thecoronary arteries, depressing a first button, piston or other controlleron the handheld controller initiates flow of contrast and in someembodiments provides feedback (for example, tactile and/or audiblefeedback). Further depressing the button on the hand controllerpreferably increases the flow rate of contras. If at any time the buttonis released, the fluid flow preferably stops and any feedback ends. This“dead-man” operability can be provided, for example, by biasing (forexample, spring loading) the first control or actuator toward the offposition. The minimum and maximum flow are preferably established by theparameters set using a graphical user interface on the display.

To deliver contrast at high flow and high pressure, for example, to theleft ventricle, a separate switch or second actuator/controller on thehand control is preferably depressed. Alternatively, a second mode ofthe first actuator/controller can be entered to control high pressureflow. In embodiments in which the handheld control provides tactilefeedback during low-pressure injection, preferably no such tactilefeedback is provided during high pressure flow. However, other feedbacksuch as an audible tone feedback different than any audible toneprovided during the low-pressure mode can be provided. Thehigh-pressure/high-flow function is preferably first input/selected fromthe parameters input/set using the graphical user interface on thedisplay. The high-flow and high-pressure injection is preferablypreprogrammed and the flow cannot be varied. As discussed above, anydirect, tactile feedback is preferably eliminated, as the pressure isoften over 1000 psi. If at any time the second button is released, theinjection preferably stops.

To deliver saline, a second or third switch, controller or actuator onthe hand controller is preferably selected, causing saline flow at apre-selected flow rate. Alternatively, a single controller or actuatorhaving three different control modes can be used. As with the otheractuators or actuator modes on the handheld controller, if at any timethe third button is released, the saline flow preferably stops.

A pressure sensor is preferably connected to a pressure isolation valveas described above. Patient pressure monitoring can be determined at anytime except when an injection of fluid exceeds the pressure set by thepressure isolation valve.

A multi-patient set can be designed so that at least some portionsthereof can safely be reused for multiple patients. In such a design,for example, the syringe and interface to contrast/saline components,disposable valves and related tubing, and a multi-use high-pressure,aseptic connector can preferably be reused for multiple patients.

Handheld controllers (whether or not in fluid connection with the fluidpath) and related tubing and check valves are preferably replaced foreach patient. Likewise, any waste port, pressure port, and the interfaceto catheter are preferably replaced for each patient. Aseptic connectorsof a multi-patient set can, for example, be wiped clean beforeconnecting a disposable se for each new patient. Reusable ormulti-patient sets preferably have a limited numbers of reuses andpreferably are not used for longer than a set period of time (forexample, an 8-hour period).

Although the present invention has been described in detail inconnection with the above embodiments and/or examples, it is to beunderstood that such detail is solely for that purpose and thatvariations can be made by those skilled in the art without departingfrom the invention. The scope of the invention is indicated by thefollowing claims rather than by the foregoing description. All changesand variations that come within the meaning and range of equivalency ofthe claims are to be embraced within their scope.

The invention claimed is:
 1. A fluid path set for use in a fluiddelivery system, comprising: a multi-patient use section adapted forconnection to a pump device and to a source of injection fluid; and aper-patient use section adapted for removable fluid communication withthe multi-patient use section, the per-patient use section comprising apressure isolation mechanism, wherein the pressure isolation mechanismcomprises: a first port adapted for connection to the pump device viathe multi-patient use section, a second port adapted for connection to apatient, a pressure isolation port adapted for connection to a source ofmedical fluid via the multi-patient use section, a lumen connecting thefirst port and the second port, and a valve member biased to a normallyopen position permitting fluid communication between the first port, thesecond port, and the pressure isolation port, and movable to a closedposition to close the pressure isolation port when fluid pressure in thelumen reaches a predetermined pressure level sufficient to overcome abiasing force applied to the valve member.
 2. The fluid path set ofclaim 1, wherein the multi-patient use section further comprises amulti-position valve adapted to selectively isolate the pump device, thesource of the injection fluid, and the per-patient use section.
 3. Thefluid path set of claim 1, further comprising a pressure transducerassociated with the pressure isolation port.
 4. The fluid path set ofclaim 1, wherein the multi-patient use section further comprises anintervening drip chamber between the source of medical fluid and thepressure isolation port.
 5. The fluid path set of claim 1, wherein themulti-patient use section is connectable to the per-patient use sectionby a pair of connectors.
 6. The fluid path set of claim 1, wherein thelumen is in fluid communication with an automated or a manual valvehaving a waste port.
 7. The fluid path set of claim 1, furthercomprising a spike for connecting the multi-patient use section with thesource of the injection fluid.
 8. The fluid path set of claim 1, whereinthe valve member comprises a spring that applies the biasing force tomaintain the valve member in the normally open position.
 9. The fluidpath set of claim 1, wherein the valve member comprises a sealingportion for sealing the pressure isolation port when the valve member isin the closed position.
 10. The fluid path set of claim 9, furthercomprising a sealing seat that contacts the sealing portion of the valvemember when the valve member is in the closed position.
 11. The fluidpath set of claim 1, wherein the valve member is linearly movablebetween the normally open position and the closed position.
 12. Thefluid path set of claim 1, wherein, in the normally open position, thepressure isolation mechanism is configured for permitting fluid flowthrough the lumen and permitting monitoring of a blood pressure of thepatient.
 13. A pressure isolation mechanism, comprising: a housingdefining a lumen with a first port, a second port, and a pressureisolation port; and a valve member disposed within the housing, thevalve member biased to a normally open position permitting fluidcommunication between the first port, the second port, and the pressureisolation port, and movable to a closed position to close the pressureisolation port when fluid pressure in the lumen reaches a predeterminedpressure level sufficient to overcome a biasing force applied to thevalve member.
 14. The pressure isolation mechanism of claim 13, furthercomprising a pressure transducer associated with the pressure isolationport.
 15. The pressure isolation mechanism of claim 13, wherein thelumen is in fluid communication with an automated or a manual valvehaving a waste port.
 16. The pressure isolation mechanism of claim 13,wherein the valve member comprises a spring that applies the biasingforce to maintain the valve member in the normally open position. 17.The pressure isolation mechanism of claim 13, wherein the valve membercomprises a sealing portion for sealing the pressure isolation port whenthe valve member is in the closed position.
 18. The pressure isolationmechanism of claim 17, wherein the housing comprises a sealing seat thatcontacts the sealing portion of the valve member when the valve memberis in the closed position.
 19. The pressure isolation mechanism of claim13, wherein the valve member is linearly movable between the normallyopen position and the closed position.
 20. The pressure isolationmechanism of claim 13, wherein, in the normally open position, thepressure isolation mechanism is configured for permitting fluid flowthrough the lumen and permitting monitoring of a patient's bloodpressure.